1. Field of the Invention
The disclosure relates to the field of display technology, and particularly to an OLED pixel structure and a method for manufacturing the same, an OLED display panel and an OLED display device having the OLED display panel.
2. Description of the Related Art
Organic Light Emitting Diode (OLED for short) is an organic thin film electroluminescence device which has advantages of simple manufacture process, low cost, flexibility of the structure, wide angle of view, etc. As a result, the displaying technology employing an Organic Light Emitting Diode has been an important displaying technology.
Whether a top emission OLED pixel structure or a bottom emission OLED pixel structure, however, it will encounter some degree of microcavity effect. Microcavity effect mainly refers to that photon densities at different energy states are reallocated such that light with certain wavelength will be emitted at certain angle once it conforms to a resonant cavity mode. Especially, as to the top emission OLED pixel structure, an electrode that is near the substrate has a higher reflectivity, while an electrode that is away from the substrate usually employs a translucent metal thin film which will increase reflection of light to generate interference among multiple photon beams between the two electrodes so as to achieve a greater microcavity effect.
For example, as shown in FIG. 1, a top emission OLED pixel structure 01 is taken as an example, and it comprises a reflective anode 11, an organic material functional layer 30, a translucent metal cathode 12 arranged in that order on a substrate 10. Both an interface between the translucent metal cathode 12 and the organic material functional layer 30 and an interface between the reflective anode 11 and the organic material functional layer 30 are planar. And, the reflective anode 11, the organic material functional layer 30 and the translucent metal cathode 12 constitute a microcavity.
With the abovementioned structure, directions of emission of the interfered photon beams generated due to the microcavity effect are almost vertical ones, which results in these problems of the narrow angle of view, and different strengths and colors of the light as being viewed from different viewing angles.